AMPK is a serine-threonine kinase, which is activated by AMP, and has three subunits, α, β and γ. In each subunit, there exist multiple isoforms (α1, α2, β1, β2, γ1, γ2 and γ3).
AMPK is involved in various physiological functions, such as suppression of gluconeogenesis and inhibition of fatty acid synthesis in liver and incorporation of sugars and an increase in fatty acid oxidation in skeletal muscles, as an energy sensor in living organisms, and has attracted attention as a target molecule of a therapeutic agent for diabetes. Therefore, an AMPK activator is expected to be effective in the treatment of diabetes as an insulin resistance improving drug, which has an insulin independent hypoglycemic effect and a lipid improving effect (Non-Patent Document 1).
Patent Documents 1 to 4 disclose a variety of compounds having an AMPK activating effect; however, a hetero ring-fused imidazole derivative like a compound of the present invention is not disclosed in any of the documents.
Patent Document 5 describes the following imidazopyridine derivatives having highly active foliar treatment ability as herbicides.

In Patent Document 5, however, an AMPK activating effect is not described.